Surgical meshes used for wall reinforcement, for example for the abdominal wall, are widely used in surgery. These surgical meshes are intended to treat, for example, hernias by temporarily or permanently filling a tissue defect. These surgical meshes are made generally from a surgical biocompatible textile and can have a number of shapes, for example rectangular, circular or oval, depending on the anatomical structure to which they are to adapt. The surgical mesh is generally flat and may vary in dimensions, from for example 5×10 cm up to 30×50 cm, depending on the size of the defect to be treated.
Before being packaged as a commercial product and shipped to hospitals or end-users, the surgical mesh has to be sterilized to prevent contamination to the patient body in which it is intended to be implanted.
Gas sterilization is commonly used in the medical field and surgical meshes are usually sterilized by means of ethylene oxide (EtO) gas.
The sterilization process generally requires the immersion of the surgical mesh in ethylene oxide for a time sufficient for the gas to sterilize the surgical mesh. For handling purposes, the surgical mesh is usually inserted into a handling pouch before being submitted to the sterilization process.
The handling pouch is provided with a window made of a material which is impervious to contamination by microorganisms, bacteria and/or a biologically active substance which may come into contact with the pouch while it is being handled, while at the same time remaining permeable to a sterilization gas such as for example ethylene oxide. Such a material is for example a nonwoven made of filaments of a high density polyethylene bound together by heat and pressure, such as a product sold by the Du Pont de Nemours under the trademark “Tyvek®”. The surgical mesh to be sterilized is therefore humidified by exposure to water vapor, inserted into a “Tyvek®” pouch and submitted to ethylene oxide gas for sterilization.
However, it may happen, in particular for large surgical meshes, that the ethylene oxide gas may not reach the entire surface of the surgical mesh and/or does not diffuse in the surgical mesh a sufficiently efficient manner when the surgical mesh is first packaged in a pouch with a “Tyvek®” window. This proves to be a problem as it is desirable that sterilization is completed to a high degree on the entire surface of the surgical mesh.
Furthermore, in order to proceed to ethylene oxide sterilization, the surgical mesh must be previously humidified. The larger the mesh, the more humid the mesh will be after the sterilization step. In addition, because of its intrinsic nature, the surgical mesh is subject to moisturization. Moisturization has to be avoided during transportation and storage so as to maintain optimal dry conditions of the surgical mesh at the moment of its use.